This invention relates to communications systems and methods, and more particularly to wireless communications systems and methods.
In recent years, wireless communication systems have emerged as an important alternative to wireline communications. These systems can offer users the convenience of mobility and personal services, as well as cost savings over traditional wireline systems in the installation and relocation of telecommunications equipment.
One type of wireless communications systems, cellular telephone systems, uses radio communications between a plurality of wireless communications terminals within the wireless system and between wireless communications terminals and the Public Switched Telephone Network (PSTN) for calls to or from outside the wireless system.
In cellular systems, a geographical area is divided into cells covered by one or more base stations. The cells are connected via a respective base station to a Mobile Services Switching Center (MSC). The MSC, in turn, is connected to the PSTN. The wireless communications terminals communicate with the MSC through the base stations. The MSC can switch calls between wireline and mobile subscribers, control signaling to the wireless communications terminals, compile billing statistics, and/or control the overall operation of the system.
Both analog and digital cellular systems have been developed. For example, analog cellular radiotelephone systems, such as designated AMPS, ETACS, NMT-450, and NMT-900, have been deployed successfully throughout the world. More recently, digital cellular radiotelephone systems such as designated IS-54B in North America and the pan-European GSM system have been introduced. Multiple mode wireless communications terminals that include, for example, both analog and digital cellular capabilities, also have been introduced.
Satellites also may be employed to perform similar functions to those performed by base stations in a conventional terrestrial radiotelephone system, for example, in areas where population is sparsely distributed over large areas or where rugged topography tends to make conventional landline telephone or terrestrial cellular telephone infrastructure technically or economically impractical. A satellite radiotelephone system typically includes one or more satellites which serve as relays or transponders between one or more earth stations and wireless communications terminals. The satellite communicates with wireless communications terminals and earth stations over duplex links. The earth station may in turn be connected to the PSTN, allowing communications between wireless communications terminals, and communications between wireless communications terminals and conventional terrestrial cellular radiotelephones or landline telephones. The satellite radiotelephone system may utilize a single antenna beam covering the entire area served by the system, or the satellite may be designed such that it produces multiple minimally-overlapping beams, each serving distinct geographical coverage areas in the system""s service region. A satellite and coverage area serve functions similar to that of a base station and cell, respectively, in a terrestrial cellular system.
It also is known to use two way unlicensed radios for wireless communications over limited distances. By using unlicensed two-way radios, the expenses associated with cellular and/or satellite radiotelephone communications may be avoided. Two-way radios include the Family Radio Service (FRS) radio that allows a group to use a small, easy to use and relatively inexpensive two-way radio for voice communications between members of the group. These radios may provide the group a choice of channels to use, to help reduce interference from other groups. FRS radios use the 460 MHz band of the radio spectrum that was allotted by the Federal Communications Commission (FCC) for narrow band two-way FM radio communications over a limited distance. See, for example, the xe2x80x9cFamily Radio Service (FRS) Information Pagexe2x80x9d at members.tripod.com.
Another example of wireless two-way radios is the Bluetooth(trademark) personal area wireless networking standard which is a low power, short range, wireless technology designed for local area voice and data communications. Bluetooth technology provides a universal radio interface in the 2.45 GHz frequency band that enables portable electronic devices to connect and communicate wirelessly via short-range ad hoc networks. Bluetooth technology is described, for example, in Haartsen, Bluetooth-The Universal Radio Interface for Ad Hoc, Wireless Connectivity, Ericsson Review No. 3, 1998, pp. 110-117, the disclosure of which is hereby incorporated herein by reference.
Embodiments of the present invention can provide a multiple-entry phonebook which may contain multiple access numbers for each entity and also may contain user preferences as to which access number to try first. The access numbers for each entity correspond to different transceivers which may be used in a wireless communications terminal to communicate, for example, with a first wireless communication system and with a second wireless communication system over a shorter distance than the first transceiver.
More specifically, according to embodiments of the present invention, a wireless communications terminal includes a first transceiver that communicates with a first wireless communications system such as a cellular communications system. A second transceiver communicates with a second wireless communications system that typically has a shorter range than the first transceiver, such as a Bluetooth or FRS system. A multiple entry phonebook includes a first wireless communications system access number and a second wireless communications system access number for each of at least one entity. The wireless communications terminal includes a controller and/or other means that determines whether to use the first wireless communications system access number or the second wireless communications system access number in response to a request to call the corresponding entity. A wireless communication is initiated with the entity over the first wireless communications system using the first transceiver access number and the first transceiver or over the second communications system using the second transceiver access number and the second transceiver, in response to this determination.
According to other embodiments of the present invention, a wireless communication is initiated with the entity over the second wireless communications system using the second transceiver access number and the second transceiver if it is determined that the second transceiver access number is preferred for wireless communications with the entity. The wireless communications terminal is connected with the entity over the second wireless communications system using the second transceiver if wireless communications with the entity are available over the second wireless communications system. The wireless communications terminal is connected with the entity over the first wireless communications system using the first transceiver if wireless communications with the entity are not available over the second wireless communications system.
According to other embodiments of the present invention, the multiple-entry phonebook includes an indicium as to whether the first wireless communications system access number or the second wireless communications system access number is preferred for wireless communications with the entity. A default indicium also may be included. The indicium may be set and/or changed using conventional wireless terminal programming techniques. Thus, in communicating with an entity a user may specify that a short range, wireless communications system such as Bluetooth or FRS should be used for communication if this mode is available. If this mode is not available then a cellular and/or satellite radiotelephone system may be used. The costs of using a cellular and/or satellite radiotelephone system therefore may be bypassed when other communications systems are available.
Embodiments of the present invention also may provide alternative communication in areas where no wireless infrastructure is present or where cellular access is difficult. For example, embodiments of the present invention may allow wireless terminals to communicate when in an isolated area, as long as the wireless communications terminals are within a certain distance of one another. Embodiments of the present invention also may allow users to communicate within large buildings such as a shopping mall or office building, where cellular radiotelephone signals may be weak. Accordingly, embodiments of the present invention can provide users with communications terminals and methods that can be cost effective and can operate in a variety of environments and conditions.